Productivity of bulls and product quality at the use of GM-soya in the diet

Abstract

Goal. To study the productive and slaughtering qualities of bulls, the chemical composition of their muscle tissue and liver for the use of various high-protein forages in the rations — narrow-leaved lupine and GM-soya. Methods. Two groups of experimental bulls were formed using the method of balanced groups. The live weight of young animals was determined by individual weighing before morning feeding, feed payment was calculated by live weight gain, and slaughter quality was determined by the technology adopted at meat processing enterprises. The chemical composition of muscle tissue and liver was determined by Kieldal, Sokslet, and combustion methods. Laboratory studies of soy, muscle tissue, and liver for the content of genetically modified organisms were carried out in the Ukrainian Laboratory of Quality and Safety of Agricultural Products. Identification of DNA in soya and products was carried out by polymerase chain reaction. Results. It was established that the studied soya contained genetically modified deoxyribonucleic acid (DNA), had the target sequence of the 35S+FMV promoter of the cauliflower mosaic virus and the NOS-terminator (nopaline synthase) of Agrobacterium tumefaciens. According to the results of the qualitative analysis of the combined samples of the internal organs of bulls (longest back muscle, lungs, liver, kidneys, spleen), genetically modified organisms were not detected in the slaughter products. Conclusions. The replacement of 40% (by mass) of wheat and 30% (by mass) of lupine pulp in the composition of the grain mixture with a similar amount of corn and genetically modified soya had a positive effect on the productive qualities of cattle (+8.5%) with lower metabolic energy costs (–4. 9%) per unit of growth. A comparative analysis of the chemical composition of the longest muscle of the back of the animals showed that in those of them that were fed a grain mixture with lupine as part of the diet, the concentration of dry matter, protein, and ash in the meat was respectively 0.19% abs., 0, 81 and 0.10% abs. higher than in animals of the experimental group. At the same time, a higher content of fat in the longest muscle of the back had the bulls fed with grain mixture with GM-soya — it amounted to 4.11%, which was 0.72% abs. more than among bulls of another group.